| /* kernel/power/earlysuspend.c |
| * |
| * Copyright (C) 2005-2008 Google, Inc. |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <linux/earlysuspend.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/rtc.h> |
| #include <linux/writeback.h> |
| #include <linux/pm_wakeup.h> |
| #include <linux/workqueue.h> |
| |
| #include "power.h" |
| |
| enum { |
| DEBUG_USER_STATE = 1U << 0, |
| DEBUG_SUSPEND = 1U << 2, |
| }; |
| static int debug_mask = DEBUG_USER_STATE; |
| module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP); |
| |
| static DEFINE_MUTEX(early_suspend_lock); |
| static DEFINE_MUTEX(suspend_lock); |
| static LIST_HEAD(early_suspend_handlers); |
| static void early_suspend(struct work_struct *work); |
| static void late_resume(struct work_struct *work); |
| static void try_to_suspend(struct work_struct *work); |
| static struct workqueue_struct *early_suspend_wq; |
| static struct workqueue_struct *suspend_wq; |
| static DECLARE_WORK(early_suspend_work, early_suspend); |
| static DECLARE_WORK(late_resume_work, late_resume); |
| static DECLARE_WORK(suspend_work, try_to_suspend); |
| static DEFINE_SPINLOCK(state_lock); |
| enum { |
| SUSPEND_REQUESTED = 0x1, |
| SUSPENDED = 0x2, |
| SUSPEND_REQUESTED_AND_SUSPENDED = SUSPEND_REQUESTED | SUSPENDED, |
| }; |
| static int state; |
| static int suspend_state; |
| static struct wakeup_source *early_suspend_ws; |
| |
| void queue_up_early_suspend_work(struct work_struct *work) |
| { |
| queue_work(early_suspend_wq, work); |
| } |
| |
| static void try_to_suspend(struct work_struct *work) |
| { |
| unsigned int initial_count, final_count; |
| |
| if (!pm_get_wakeup_count(&initial_count, true)) |
| goto queue_again; |
| |
| mutex_lock(&suspend_lock); |
| |
| if (!pm_save_wakeup_count(initial_count) || |
| system_state != SYSTEM_RUNNING) { |
| mutex_unlock(&suspend_lock); |
| goto queue_again; |
| } |
| |
| if (suspend_state == PM_SUSPEND_ON) { |
| mutex_unlock(&suspend_lock); |
| return; |
| } |
| |
| if (suspend_state >= PM_SUSPEND_MAX) |
| hibernate(); |
| else |
| pm_suspend(suspend_state); |
| |
| mutex_unlock(&suspend_lock); |
| |
| if (!pm_get_wakeup_count(&final_count, false)) |
| goto queue_again; |
| |
| /* |
| * If the wakeup occured for an unknown reason, wait to prevent the |
| * system from trying to suspend and waking up in a tight loop. |
| */ |
| if (final_count == initial_count) |
| schedule_timeout_uninterruptible(HZ / 2); |
| |
| queue_again: |
| queue_work(suspend_wq, &suspend_work); |
| } |
| |
| void register_early_suspend(struct early_suspend *handler) |
| { |
| struct list_head *pos; |
| |
| mutex_lock(&early_suspend_lock); |
| list_for_each(pos, &early_suspend_handlers) { |
| struct early_suspend *e; |
| e = list_entry(pos, struct early_suspend, link); |
| if (e->level > handler->level) |
| break; |
| } |
| list_add_tail(&handler->link, pos); |
| if ((state & SUSPENDED) && handler->suspend) |
| handler->suspend(handler); |
| mutex_unlock(&early_suspend_lock); |
| } |
| EXPORT_SYMBOL(register_early_suspend); |
| |
| void unregister_early_suspend(struct early_suspend *handler) |
| { |
| mutex_lock(&early_suspend_lock); |
| list_del(&handler->link); |
| mutex_unlock(&early_suspend_lock); |
| } |
| EXPORT_SYMBOL(unregister_early_suspend); |
| |
| static void early_suspend(struct work_struct *work) |
| { |
| struct early_suspend *pos; |
| unsigned long irqflags; |
| int abort = 0; |
| |
| mutex_lock(&early_suspend_lock); |
| spin_lock_irqsave(&state_lock, irqflags); |
| if (state == SUSPEND_REQUESTED) |
| state |= SUSPENDED; |
| else |
| abort = 1; |
| spin_unlock_irqrestore(&state_lock, irqflags); |
| |
| if (abort) { |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("early_suspend: abort, state %d\n", state); |
| mutex_unlock(&early_suspend_lock); |
| goto abort; |
| } |
| |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("early_suspend: call handlers\n"); |
| list_for_each_entry(pos, &early_suspend_handlers, link) { |
| if (pos->suspend != NULL) |
| pos->suspend(pos); |
| } |
| mutex_unlock(&early_suspend_lock); |
| |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("early_suspend: after call handlers\n"); |
| /* just wake up flusher to start write back and don't wait it finished*/ |
| wakeup_flusher_threads(0, WB_REASON_SYNC); |
| abort: |
| spin_lock_irqsave(&state_lock, irqflags); |
| if (state == SUSPEND_REQUESTED_AND_SUSPENDED) |
| __pm_relax(early_suspend_ws); |
| spin_unlock_irqrestore(&state_lock, irqflags); |
| queue_work(suspend_wq, &suspend_work); |
| } |
| |
| static void late_resume(struct work_struct *work) |
| { |
| struct early_suspend *pos; |
| unsigned long irqflags; |
| int abort = 0; |
| |
| mutex_lock(&early_suspend_lock); |
| spin_lock_irqsave(&state_lock, irqflags); |
| if (state == SUSPENDED) |
| state &= ~SUSPENDED; |
| else |
| abort = 1; |
| spin_unlock_irqrestore(&state_lock, irqflags); |
| |
| if (abort) { |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("late_resume: abort, state %d\n", state); |
| goto abort; |
| } |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("late_resume: call handlers\n"); |
| list_for_each_entry_reverse(pos, &early_suspend_handlers, link) |
| if (pos->resume != NULL) |
| pos->resume(pos); |
| if (debug_mask & DEBUG_SUSPEND) |
| pr_info("late_resume: done\n"); |
| abort: |
| mutex_unlock(&early_suspend_lock); |
| } |
| |
| void request_suspend_state(suspend_state_t new_state) |
| { |
| unsigned long irqflags; |
| int old_sleep; |
| suspend_state_t prev_state; |
| |
| mutex_lock(&suspend_lock); |
| prev_state = suspend_state; |
| spin_lock_irqsave(&state_lock, irqflags); |
| old_sleep = state & SUSPEND_REQUESTED; |
| if (debug_mask & DEBUG_USER_STATE) { |
| struct timespec ts; |
| struct rtc_time tm; |
| getnstimeofday(&ts); |
| rtc_time_to_tm(ts.tv_sec, &tm); |
| pr_info("request_suspend_state: %s (%d->%d) at %lld " |
| "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n", |
| new_state != PM_SUSPEND_ON ? "sleep" : "wakeup", |
| prev_state, new_state, |
| ktime_to_ns(ktime_get()), |
| tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, |
| tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec); |
| } |
| if (!old_sleep && new_state != PM_SUSPEND_ON) { |
| state |= SUSPEND_REQUESTED; |
| queue_up_early_suspend_work(&early_suspend_work); |
| } else if (old_sleep && new_state == PM_SUSPEND_ON) { |
| state &= ~SUSPEND_REQUESTED; |
| __pm_stay_awake(early_suspend_ws); |
| queue_up_early_suspend_work(&late_resume_work); |
| } |
| suspend_state = new_state; |
| spin_unlock_irqrestore(&state_lock, irqflags); |
| mutex_unlock(&suspend_lock); |
| } |
| |
| int __init early_suspend_init(void) |
| { |
| int ret = 0; |
| |
| early_suspend_ws = wakeup_source_register("early_suspend"); |
| |
| if (!early_suspend_ws) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| early_suspend_wq = alloc_ordered_workqueue("early_suspend", 0); |
| |
| if (!early_suspend_wq) { |
| ret = -ENOMEM; |
| goto ws_err; |
| } |
| |
| suspend_wq = alloc_ordered_workqueue("auto_suspend", 0); |
| |
| if (!suspend_wq) { |
| ret = -ENOMEM; |
| goto es_wq_err; |
| } |
| |
| goto out; |
| |
| es_wq_err: |
| destroy_workqueue(early_suspend_wq); |
| ws_err: |
| wakeup_source_unregister(early_suspend_ws); |
| out: |
| return ret; |
| } |